Anaplasmosis is a tick-borne disease caused by the bacterium Anaplasma phagocytophilum. It was previously known as human granulocytic ehrlichiosis (HGE) and has more recently been called human granulocytic anaplasmosis (HGA). Anaplasmosis is transmitted to humans by tick bites primarily from the black-legged tick (Ixodes scapularis) and the western black-legged tick (Ixodes pacificus). Of the four distinct phases in the tick life-cycle (egg, larvae, nymph, adult), nymphal and adult ticks are most frequently associated with transmission of anaplasmosis to humans. Typical symptoms include: fever, headache, chills, and muscle aches. Usually, these symptoms occur within 1-2 weeks of a tick bite. Anaplasmosis is initially diagnosed based on symptoms and clinical presentation, and later confirmed by the use of specialized laboratory tests.

Babesiosis

Babesiosis is a malaria-like, parasitic infection that infects red blood cells and are spread by the bite of the Ixodes tick (black-legged tick). Most human cases of Babesia infection in the United States are caused by the parasite Babesia microti. Occasional cases caused by other species (types) of Babesia have been detected. Babesia microti is spread in nature by Ixodes scapularis ticks (also called black-legged ticks or deer ticks). The symptoms of Babesiosis normally begin about a week after a tick bite with a gradual onset of malaise, anorexia and fatigue. This is followed several days later by high fever, drenching sweats, muscle pain and headaches. As with malaria, these symptoms can continue over a protracted period or can abate, then recur. Babesia infection can range in severity from asymptomatic to life-threatening.

Ehrlichiosis

Ehrlichiosis is the general name used to describe several bacterial diseases that affect animals and humans. Human ehrlichiosis is a disease caused by at least three different ehrlichial species in the United States: Ehrlichia chaffeensis, Ehrlichia ewingii, and a third Ehrlichia species provisionally called Ehrlichia muris-like (EML). Ehrlichiae are transmitted to humans by the bite of an infected tick. The lone star tick (Amblyomma americanum) is the primary vector of both Ehrlichia chaffeensis and Ehrlichia ewingii in the United States. Typical symptoms include: fever, headache, fatigue, and muscle aches. Usually, these symptoms occur within 1-2 weeks following a tick bite. Ehrlichiosis is diagnosed based on symptoms, clinical presentation, and later confirmed with specialized laboratory tests.

Rocky Mountain Spotted Fever (RMSF)

Rocky Mountain spotted fever (RMSF) is a tick-borne disease caused by the bacterium Rickettsia rickettsii. This organism is a cause of potentially fatal human illness in North and South America, and is transmitted to humans by the bite of infected tick species. In the United States, these include the American dog tick (Dermacentor variabilis), Rocky Mountain wood tick (Dermacentor andersoni), and brown dog tick (Rhipicephalus sanguineus). Typical symptoms include: fever, headache, abdominal pain, vomiting, and muscle pain. A rash may also develop, but is often absent in the first few days, and in some patients, never develops. Rocky Mountain spotted fever can be a severe or even fatal illness if not treated in the first few days of symptoms. The initial diagnosis is made based on clinical signs and symptoms, medical history, can later be confirmed by using specialized laboratory tests.